1. A focal reducing attachment having an object side, an image side, an optical power \u03c6, a magnification M, and comprising:
a total of five or six lens elements arranged in four lens groups G1, G2, G3 and G4 in order from the object side to the image side, and wherein:
a) lens group G1 has an optical power \u03c6G1, wherein \u22121<\u03c6G1\u03c6<\u22120.001, and including a most object-side-wise negative lens element that defines a most object-side-wise concave surface;
b) lens group G2 has positive power and has a positive lens element with a most object-side facing surface having a curvature CvOb2;
c) lens group G3 having negative power and having a negative lens element with a most image-side-facing surface having a curvature CvIm3;
d) a positive powered lens group G4; and
wherein 2<(CvOb2+CvIm3)\u03c6<30 and 0.3<M<1.0.
2. A focal reducing attachment according to claim 1 in which any one of the four lens groups G1, G2, G3 and G4 comprises a cemented or air-spaced doublet.
3. A focal reducing attachment according to claim 1 in which any two of the four lens groups G1, G2, G3 and G4 comprises a cemented or air-spaced doublet.
4. A focal reducing attachment according to claim 1 in which lens group G2 comprises a cemented or air-spaced doublet, and in which lens groups G1, G3, and G4 each consists of a single lens element.
5. A focal reducing attachment according to claim 1 in which group G4 comprises a cemented or air-spaced doublet and in which lens groups G1, G2 and G3 each consists of a single element.
6. A focal reducing attachment according to claim 1 in which both lens groups G2 and G4 comprise either a cemented doublet or an air-spaced doublet, and in which lens groups G1 and G3 each consists of a single element.
7. A focal reducing attachment according to claim 1, wherein the magnification M is in the range 0.45<M<0.9.
8. A focal reducing attachment according to claim 1, wherein the lens group G4 includes a most image-side-wise surface that is either plano or convex.
9. A focal reducing attachment according to claim 1, wherein VT a vertex length, and wherein 0.05.<VT\xb7\u03c6<1.0.
10. A focal reducing attachment according to claim 1, wherein 0.15.<VT\xb7\u03c6<0.65.
11. A focal reducing attachment according to claim 1, wherein the object side is configured to interface with an SLR lens and the image side is configured to interface with a mirrorless camera.
12. A lens system comprising:
the focal reducing attachment of claim 1; and
the objective lens operably attached to the focal reducer.
13. A camera system, comprising:
the lens system of claim 12; and
a mirrorless camera having a camera body with a mounting flange, wherein the lens system is operably attached to the camera body at the mounting flange.
14. A camera system according to claim 13, wherein the mirrorless camera includes a camera body having an interior in which the one or more parallel plates are disposed.
15. A focal reducing attachment according to claim 1, wherein the objective lens has a vertex length, and wherein the focal-reducing attachment and the objective lens define a combined vertex length that is less than the objective lens vertex length.
16. A focal reducing attachment for use with an objective lens and consisting
of, in order from an object side to an image side:
a first lens group G1 having a first negative power and a most object-side concave surface;
a second lens group G2 having a first positive power and a most object-side surface having a curvature CvOb2;
a third lens group G3 having a second negative power greater than the first negative power and having a most image-side surface having a curvature CvIm3;
a fourth lens group G4 having a second positive power and a most image-side surface;
one or more plane parallel plates that reside between the image sensor and the fourth lens element; and
wherein the focal reducing attachment has an overall power \u03c6 such that (CvOb2+CvIm3)\u03c6>3 and an overall magnification M such that 0.4\u2266M\u22661; and
wherein at least one of the lens groups G2 or G4 comprises a cemented or air-spaced doublet.
17. The focal reducing attachment according to claim 16, wherein at least one of the one or more plane parallel plates comprises a filter.
18. A lens system comprising:
the focal reducing attachment of claim 16; and
the objective lens operably attached to the focal reducer.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A hydroelectric wave-energy conversion device comprising:
a buoyant apparatus having at least one buoyant component; a multi-directional to linear motion conversion apparatus connected to said buoyant apparatus, wherein said at least one buoyant component is configured to fold between a substantially perpendicular plane and a substantially parallel plane in relation to said multi-directional to linear motion conversion apparatus; and an anchoring apparatus connected to said conversion apparatus.
2. The hydroelectric wave-energy conversion apparatus of claim 1, wherein said at least one buoyant component folds in relation to said multi-directional to linear motion conversion apparatus when at least one of:
at least one vectorial component of a sea wave impinges on said at least one buoyant component; and at least one of an unusual environmental condition and an unusual climate condition creates a sea wave with an above-average height.
3. The hydroelectric wave-energy conversion apparatus of claim 2, wherein said at least one buoyant component folds in a substantially parallel plane in relation to said multi-directional to linear motion conversion apparatus to allow sea submersion of said at least one buoyant component.
4. The hydroelectric wave-energy conversion device of claim 1, wherein said buoyant apparatus comprises: a light gage metal casing including a reinforcing means and a buoyant material filing.
5. The hydroelectric wave-energy conversion device of claim 1, wherein said multi-directional to linear motion conversion apparatus comprises: a first pipe and a second pipe coaxially located inside said first pipe.
6. The hydroelectric wave-energy conversion device of claim 5, wherein said multi-directional to linear motion conversion apparatus further comprises: a pistoncylinder arrangement coaxially located inside said second pipe.
7. The hydroelectric wave-energy conversion device of claim 6, wherein at least a part of said cylinder is fixedly attached in relation to said second pipe.
8. The hydroelectric wave-energy conversion device of claim 6, wherein said piston comprises a first end portion connected to a first tension means and a second end portion connected to a second tension means.
9. The hydroelectric wave-energy conversion device of claim 8, wherein said first tension means comprises a first pulley arrangement and said second tension means comprises a second pulley arrangement.
10. The hydroelectric wave-energy conversion device of claim 9, wherein said first tension means further comprises a first pulling means in mechanical relationship with said first pulley arrangement; and said second tension means further comprises a second pulling means in mechanical relationship with said second pulley arrangement.
11. The hydroelectric wave-energy conversion device of claim 10, wherein said first and second pulling means comprises at least one of: steel chain, steel cable or any combination thereof.
12. The hydroelectric wave-energy conversion device of claim 8, wherein said piston further comprises: a double acting piston which is upwardly and downwardly pulled by said first and second tension means, alternately.
13. The hydroelectric wave-energy conversion device of claim 12, wherein said pistoncylinder arrangement further comprises: at least one check valve allowing the inflow of at least one of: a fluid and a gas; and at least one check valve allowing the outflow of said at least one of: a fluid and a gas, while said double acting piston is upwardly and downwardly pulled.
14. The hydroelectric wave-energy conversion device of claim 13, wherein said at least one of: a fluid and a gas is received at a motorgenerator arrangement located in at least one of: a land location remotely located form said wave-energy conversion device; and integrated into said wave-energy conversion device.
15. The hydroelectric wave-energy conversion device of claim 1, wherein said anchoring apparatus comprises: a rotating component in mechanical relationship with a holding means sufficiently buried under the sea floor; said rotating component allowing angular motion of said hydroelectric wave-energy conversion device in relation to the sea floor.
16. A hydroelectric wave-energy conversion system comprising: at least one of the hydroelectric wave-energy conversion device of claim 1.
17. The hydroelectric wave-energy conversion system of claim 16, wherein a plurality of hydroelectric wave-energy conversion devices is selectively interconnected in at least one of: a series arrangement, a parallel arrangement, or a combination thereof.
18. The hydroelectric wave-energy conversion system of claim 17, wherein kinetic energy converted by said conversion system is directed to a land-located pressurized stabilizing tank that stores said kinetic energy as potential energy.
19. The hydroelectric wave-energy conversion system of claim 18, wherein said stored potential energy is used to at least one of: compensate for any lack of converted energy and maintain a predetermined power capacity.